Ryle on Dispositions and Hypotheticals

Paper by Robert W. Burc

Two Basic Claims of Phenomenology

Paper by Robert W. Burc

Valental aspects of Peircean algebraic logic

AbstractThis paper describes a system of logic that has both an algebraic syntax and a graphical syntax and that may be regarded as a kind of semantic net. The paper analyses certain “valental” characteristics of terms and graphs of this logical system: characteristics defined in terms of the “valence”, or number of argument-places, in the terms and graphs. The most famous valental result is the so-called “Reduction Thesis” of Charles Sanders Peirce. The paper briefly explicates the author's proof, which is to be published in a forthcoming book, of this Reduction Thesis. Several additional valental results are proved, and the potential of PAL as a bridge between logic and topological graph theory is suggested

A comparison of the mismatch negativity (MMN) event-related potential to tone and speech stimuli in normal and aphasic adults

We evaluated the mismatch negativity (MMN) event-related potential (ERP) in normal and aphasic adults to tone and speech stimuli to determine aphasic patients' auditory discrimination and the relationship between MMN measures and severity of aphasia. MMNs were present in 89 % of normal subjects and 79 % of aphasic subjects to tone stimuli. MMNs were present in 100% of normal subjects and 54 % of aphasic subjects to speech stimuli. The duration of the MMN ERP to speech stimuli was significantly related to severity of aphasia on the Western Aphasia Battery, Porch Index of Communicative Ability, and the Token Test. Thus, not all aphasic people show an early, preconscious orientation response to tone and speech stimuli. However, the duration of this response, when present, to speech stimuli appears to be related to the severity of aphasia

Architecture and secondary structure of an entire HIV-1 RNA genome

Single-stranded RNA viruses encompass broad classes of infectious agents and cause the common cold, cancer, AIDS, and other serious health threats. Viral replication is regulated at many levels, including using conserved genomic RNA structures. Most potential regulatory elements within viral RNA genomes are uncharacterized. Here we report the structure of an entire HIV-1 genome at single nucleotide resolution using SHAPE, a high-throughput RNA analysis technology. The genome encodes protein structure at two levels. In addition to the correspondence between RNA and protein primary sequences, a correlation exists between high levels of RNA structure and sequences that encode inter-domain loops in HIV proteins. This correlation suggests RNA structure modulates ribosome elongation to promote native protein folding. Some simple genome elements previously shown to be important, including the ribosomal gag-pol frameshift stem-loop, are components of larger RNA motifs. We also identify organizational principles for unstructured RNA regions. Highly used splice acceptors lie in unstructured motifs and hypervariable regions are sequestered from flanking genome regions by stable insulator helices. These results emphasize that the HIV-1 genome and, potentially, many coding RNAs are punctuated by numerous previously unrecognized regulatory motifs and that extensive RNA structure may constitute an additional level of the genetic code

The QCD spectrum with three quark flavors

We present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks - two light and one strange, and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge action and an improved Kogut-Susskind quark action. The lattice spacings, and hence also the physical volumes, were tuned to be the same in all the runs to better expose differences due to flavor number. Lattice spacings were tuned using the static quark potential, so as a byproduct we obtain updated results for the effect of sea quarks on the static quark potential. We find indications that the full QCD meson spectrum is in better agreement with experiment than the quenched spectrum. For the 0++ (a0) meson we see a coupling to two pseudoscalar mesons, or a meson decay on the lattice.Comment: 38 pages, 20 figures, uses epsf. 5/29/01 revision responds to referee's Comments, changes pion fits and tables, and corrects Fig. 10 and some minor error

MMS Study of the Structure of Ionâ Scale Flux Ropes in the Earth’s Crossâ Tail Current Sheet

This study analyzes 25 ionâ scale flux ropes in the Magnetospheric Multiscale (MMS) observations to determine their structures. The high temporal and spatial resolution MMS measurements enable the application of multispacecraft techniques to ionâ scale flux ropes. Flux ropes are identified as quasiâ oneâ dimensional (quasiâ 1â D) when they retain the features of reconnecting current sheets; that is, the magnetic field gradient is predominantly northward or southward, and quasiâ 2â D when they exhibit circular cross sections; that is, the magnetic field gradients in the plane transverse to the flux rope axis are comparable. The analysis shows that the quasiâ 2â D events have larger core fields and smaller pressure variations than the quasiâ 1â D events. These two types of flux ropes could be the result of different processes, including magnetic reconnection with different dawnâ dusk magnetic field components, temporal transformation of flattened structure to circular, or interactions with external environments.Plain Language SummaryMagnetic flux ropes are fundamental magnetic structures in space plasma physics and are commonly seen in the universe, such as, astrophysical jets, coronal mass ejections, and planetary magnetospheres. Flux ropes are important in mass and energy transport across plasma and magnetic boundaries, and they are found in a wide range of spatial sizes, from several tens of kilometers, that is, ionâ scale flux ropes, to tens of millions of kilometers, that is, coronal mass ejections, in the solar system. The ionâ scale flux ropes can be formed during magnetic reconnection and are hypothesized to energize electrons and influence the reconnection rate. Previous examinations of the structure of ionâ scale flux ropes were greatly limited by measurement resolution. The unprecedented Magnetospheric Multiscale (MMS) mission high temporal and spatial resolution measurements provide a unique opportunity to investigate flux rope structures. By employing multispacecraft techniques, this study has provided new insights into the magnetic field variations and dimensionality of ionâ scale flux ropes in the Earth’s magnetotail. The results are consistent with the evolution of ionâ scale flux ropes from initially flattened current sheetâ like flux ropes near the time of formation into lower energy state with circular cross section predicted by theory and termed as the â Taylorâ state.Key PointsIonâ scale flux ropes are observed to have either flattened or circular cross sections using MDD and GS reconstructionAnalysis of 25 flux ropes show that circular crossâ section flux ropes have stronger core field and smaller thermal pressures than flattened flux ropesThe two types of flux ropes may be the results of reconnection, temporal evolution, or interactions with external environmentPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150544/1/grl59049.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150544/2/grl59049_am.pd

Characteristics of Minor Ions and Electrons in Flux Transfer Events Observed by the Magnetospheric Multiscale Mission

In this study, the ion composition of flux transfer events (FTEs) observed within the magnetosheath proper is examined. These FTEs were observed just upstream of the Earth\u27s postnoon magnetopause by the National Aeronautics and Space Administration (NASA) Magnetospheric Multiscale (MMS) spacecraft constellation. The minor ion characteristics are described using energy spectrograms, flux distributions, and ion moments as the constellation encountered each FTE. In conjunction with electron data and magnetic field observations, such observations provide important contextual information on the formation, topologies, and evolution of FTEs. In particular, minor ions, when combined with the field-aligned streaming of electrons, are reliable indicators of FTE topology. The observations are also placed (i) in context of the solar wind magnetic field configuration, (ii) the connection of the sampled flux tube to the ionosphere, and (iii) the location relative to the modeled reconnection line at the magnetopause. While protons and alpha particles were often depleted within the FTEs relative to the surrounding magnetosheath plasma, the He+ and O+ populations showed clear enhancements either near the center or near the edges of the FTE, and the bulk plasma flow directions are consistent with magnetic reconnection northward of the spacecraft and convection from the dayside toward the flank magnetopause

Kinetic Interaction of Cold and Hot Protons With an Oblique EMIC Wave Near the Dayside Reconnecting Magnetopause

We report observations of the ion dynamics inside an Alfvén branch wave that propagates near the reconnecting dayside magnetopause. The measured frequency, wave normal angle and polarization are consistent with the predictions of a dispersion solver. The magnetospheric plasma contains hot protons (keV), cold protons (eV), plus some heavy ions. While the cold protons follow the magnetic field fluctuations and remain frozen-in, the hot protons are at the limit of magnetization. The cold protons exchange energy back and forth, adiabatically, with the wave fields. The cold proton velocity fluctuations contribute to balance the Hall term fluctuations in Ohm's law, and the wave E field has small ellipticity and right-handed polarization. The dispersion solver indicates that increasing the cold proton density facilitates propagation and amplification of these waves at oblique angles, as for the observed wave